High performance aircraft structures and engines are often utilized at elevated temperature conditions approaching 260.degree. C. Titanium, aluminum, and aluminum-lithium alloys are currently used under these conditions. Titanium alloys such as Ti-6Al-4V have desirably high strengths but have undesirably high densities. Aluminum alloys, on the other hand, have desirably low densities, but have undesirably low strengths and an undesirably severe loss of strength at temperatures above 150.degree. C. Aluminum-lithium alloys do have an attractive combination of very low density and high ambient temperature strength. However, previous work on aluminum-lithium alloys produced by conventional and rapid solidification processes has shown significant degradation in strength when exposed to temperatures above 75.degree. C. for periods greater than one hour.
Accordingly, it is an object of this invention to provide aluminum-lithium alloys which have the desirable combination of low density and high strength.
It is a further object of this invention to obtain the above object at operating temperatures ranging from 25.degree. C. to 260.degree. C.
It is a further object of this invention to accomplish the above objects for increased operational periods.
Other objects and advantages of this invention will become apparent hereinafter the specification and drawings which follow.